Dana-Farber Cancer Institute established the Molecular Biology Core Facilities to provide Institute laboratories convenient and cost-effective access to various molecular biology techniques and reagents such as oligonucleotides, synthetic peptides, microprotein sequencing, mass analysis, DNA sequencing, genotyping, and protein-ligand analysis. As these services became established and usage increased, the instrumentation has been continually upgraded, replaced and augmented by new instrumentation. Automated DNA sequencing and genotyping was first established in 1990 and has undergone the most dramatic growth of all the services. Each year the number of successful sequencing reactions has increased by 35 percent and still shows no signs of leveling off. The current instrumentation for DNA sequencing and genotyping includes three model 373A sequencers and one model 377 sequencer all from PE Biosystems, the first model 373 originally purchased in 1990. One model 2400, one model 9600 and one model 9700 thermal cycler are used for dye terminator cycle sequencing. This facility is integrated with the DNA synthesis facility which provides oligonucleotides for DNA sequencing and genotyping projects. The DNA synthesis facility currently uses one model 3948 and one model 394, both from PE Biosystems. This proposal requests funds to purchase a model 377 automated DNA sequencer with 96 capacity upgrade from PE Biosystems and a Tetrad thermal cycler from MJ Research to expand the capacity as well as upgrade the facility instrumentation by replacing some of the older model 373 sequencers. By purchasing these instruments, the facility will be able to change over to a 96 format for all aspects of the DNA sequencing and genotyping protocols for a more efficient operation. Institute commitment and a proven chargeback system to cover operating costs are well in place for the expansion of the facility.